DIY LED - Group Buy

[mason dixon]

Thanks, I was thinking that can't be right but I had to ask since I'm such a noob.

Will 1 24v laptop pwm be enough for 72 led's?

[sphelps]

Originally Posted by mason dixon

Thanks, I was thinking that can't be right but I had to ask since I'm such a noob.

Will 1 24v laptop pwm be enough for 72 led's?

Probably not but it depends on the wattage of the power supply, how many watts or amps is it rated for?

For 72 LEDs you'll need at least 200W which I believe is much more than the average laptop requires. You can buy other power supplies that run at 24V at much higher wattage than a laptop supply. I would go larger to the range of 300-350 W encase you ever wanted to add more LEDs.

[StirCrazy]

for a power supply you don't want to go by watts. while this can work it is much easier and safer to go with a constant curent output. so figure out what current you want to run at (700mA or 1000mA) then get one that has enough voltage to handle the amount of LEDs. you want to run your blues on a different power than your whites

here is an example of one of the better drivers to come out laitly
http://www.nanotuners.com/product_in...roducts_id=754

this is a 64 top 114 volt driver at 1050mA you can get them bigger or smaller.

Steve

[sphelps]

Steve are you talking about a power supply or driver? If the driver runs off 120VAC then obviously you don't need a power supply but some drivers already discussed require a lower voltage DC supply so you need a separate power supply. The driver must be constant current but the power supply only needs to have enough power (watts) to run the driver(s). The voltage of the supply is also important and dependent on how many LEDs are in each array for each driver.

[Bryan]

Originally Posted by StirCrazy

here is an example of one of the better drivers to come out laitly
http://www.nanotuners.com/product_in...roducts_id=754

this is a 64 top 114 volt driver at 1050mA you can get them bigger or smaller.

Steve

I would recommend unless you are experienced working/designing around electricity stick with a lower voltage, 65-115 dc can be dangerous. You may want to look at a 24vdc 10-15 amp power supply, and use multiple drivers in parallel.

[StirCrazy]

Originally Posted by sphelps

Steve are you talking about a power supply or driver? If the driver runs off 120VAC then obviously you don't need a power supply but some drivers already discussed require a lower voltage DC supply so you need a separate power supply. The driver must be constant current but the power supply only needs to have enough power (watts) to run the driver(s). The voltage of the supply is also important and dependent on how many LEDs are in each array for each driver.

I am tazlking about a driver and power supply in one unit. I have looked at both ways and find no advantage to one over the other aside from a all in one unit "can" under the right situations be cheeper and the end result is usaly much cleaner.

the units I was talking about will self adjust to a requirment between 64 and 114 volts. the TR are a little more cost wise than meanwell but they have the higher capacity ie. this one will handle about 33 LEDs (max), they dont have the inrush problem that the mean wells have. as well as they also have a built in 10V reference voltage so for manual dimming all that is required is a pot.

heres a link to the info sheet on them http://www.thomasresearchproducts.co...2001-31-11.pdf


Steve

[StirCrazy]

Originally Posted by Bryan

I would recommend unless you are experienced working/designing around electricity stick with a lower voltage, 65-115 dc can be dangerous. You may want to look at a 24vdc 10-15 amp power supply, and use multiple drivers in parallel.

anyone who is considering building a LED fixture should not be unexperienced with electricity in the first place. besides as little as 35Vdc can give you a hell of a jolt, more so if the power supply allows for higher currents, the TR does have short circuit protection which should tell you if something is wrong the first time you plug it in

think about what were doing here. we're soldering a ton of wires to pads on a hunk of aluminum and suspending it over a tank of water... what is safe about this in the first place? as with any DIY involving electricity, this is not for some one who doesn't feel confident working with electricity and there skills to do so.

I am actually testing a couple ways to electrically isolate everything after it is together, for a few reasons. one - so humidity can condensate and make a water drop shorting out a led to the heat sink, two - so you don't bump a bare wire while your working by the light, and 3 - to prevent corrosion of the solder joints from salt creep and humidity. when I find one I am happy with I'll post it, but so far the liquid electrical tape is looking pretty good.

Steve

[sphelps]

Originally Posted by StirCrazy

I am tazlking about a driver and power supply in one unit. I have looked at both ways and find no advantage to one over the other aside from a all in one unit "can" under the right situations be cheeper and the end result is usaly much cleaner.

The major advantage of using a separate power supply is having the ability to adjust the supply voltage to match the number and type of LEDs which results in higher efficiency. In addition it's cheaper up front and long term if you ever have any failures. With an all in one drivers you're paying for multiple power supplies in each driver as appose to using one single power supply for all your LEDs. If a single part fails in one an AIO driver you're pretty much forced to replace the whole thing which can be expensive if you're paying $100+ a driver. Using a separate power supply will allow you to easily replace individual inexpensive drivers for a fraction of the cost and if your power supply failed they are not too expensive and can even be purchased locally so you won't have any down time.

As for a cleaner look I guess it depends on your design, but I think the AIOs are bulky and having a large number of them makes things the opposite of clean. Using a separate power supply means one power supply that can be installed virtually anywhere like under the stand or in an electrical compartment and the drivers are very low profile and can be as small as a couple square inches making them very east to build into your heat sink.

I've also noticed a lot of the stand alone drivers offer both 0-10V and PWM control so if you're not sure which one you want to use the option will always be there without having to change out drivers down the road.

The AIO have the advantage of simplicity and perhaps better suited for smaller builds only requiring one or two drivers. But for larger lighting systems which use many drivers for more levels of control I think the stand alone approach is the way to go.

[StirCrazy]

Originally Posted by sphelps

The major advantage of using a separate power supply is having the ability to adjust the supply voltage to match the number and type of LEDs which results in higher efficiency. In addition it's cheaper up front and long term if you ever have any failures. With an all in one drivers you're paying for multiple power supplies in each driver as appose to using one single power supply for all your LEDs. If a single part fails in one an AIO driver you're pretty much forced to replace the whole thing which can be expensive if you're paying $100+ a driver. Using a separate power supply will allow you to easily replace individual inexpensive drivers for a fraction of the cost and if your power supply failed they are not too expensive and can even be purchased locally so you won't have any down time.

As for a cleaner look I guess it depends on your design, but I think the AIOs are bulky and having a large number of them makes things the opposite of clean. Using a separate power supply means one power supply that can be installed virtually anywhere like under the stand or in an electrical compartment and the drivers are very low profile and can be as small as a couple square inches making them very east to build into your heat sink.

I've also noticed a lot of the stand alone drivers offer both 0-10V and PWM control so if you're not sure which one you want to use the option will always be there without having to change out drivers down the road.

The AIO have the advantage of simplicity and perhaps better suited for smaller builds only requiring one or two drivers. But for larger lighting systems which use many drivers for more levels of control I think the stand alone approach is the way to go.

I am not sure where your getting your drivers for your fixture but 15 bucks for 6 or 7 LEDs is a good deal, then you have to buy a power supply on top of that.. so price wise not realy to much difference but sure maybe some.

the problem I have found with the stand alones are that they are all based on a 10V for PWN amd volatage, while this isn't a real problem it does involve building a new circut if you use any ardruno based setup, as they are only a 5V PWM signal, and if you want to build 0-10V you need to have a seperate wall wart and circut to supply the referance voltage.

as for the cleaner look, if you use meanwells which are so 2010 ya you will need one unit for every 13 LEDs so on a large build you will need more of them, which is the beauty of the newer TR drivers as you can get them in different sizes up to ones that will do between 25 (min) and 82(max) LEDs in series with one constant current driver so a very large build can have two drivers measuring 2" x 10" each which don't have to be in the fixture, but rather behind the stand or what ever. you have to remember for each little driver you put in the fixture you have to figure there heat output into the capability of the heat sink. take "steve's" drivers.. they are the cheepest I have found at 15 bucks each on sale that are a nice Driver ( will take ardruno input from the box and also 10V control) but they have to be mounted to a heat sink of some kind and disapate 6 watts for a single channel driver so on a large build that will add substantualy to the requirments of the heat sink. oh and they will only handle 6 or 7 LEDs per channel.

Steve

[WindowMaker]

This is really old, but did these ever get ordered? I could go for about 30 of the blue if someone has spares or is interested in a split.